Electrically powered vehicles each have a power storage device (for example, a secondary battery, a capacitor, or the like) mounted thereon, and travel using driving force generated from electric power stored in the power storage device. The electrically powered vehicles include, for example, an electric vehicle, a hybrid vehicle, a fuel cell vehicle, and the like.
In recent years, a technique has been proposed to charge the power storage device mounted on each of such vehicles, using a commercial electric power source with high power generation efficiency. It can be expected that the use of such a technique achieves increased fuel consumption efficiency of a hybrid vehicle, for example. Drawing attention in particular is a technique that employs a commercial electric power source provided at each home (for example, a supply source of relatively low voltage such as 100 V or 200 V) in order to charge the power storage device mounted on the electrically powered vehicle.
For a user who uses the electrically powered vehicle that can be charged by the commercial electric power source, it is more preferable if a fee for an amount of electric power required in charging the power storage device is cheaper. If fee for usage of electric power in midnight is cheaper than that in daytime, expenses for charging can be reduced by, for example, charging the power storage device of the electrically powered vehicle during a period of midnight power.
However, depending on the user's circumstances, it may be difficult to perform operations for charging the electrically powered vehicle in midnight. For example, if the user uses the electrically powered vehicle in daytime and has to wait until midnight to start the operations of charging, the user is likely to suffer from an increased burden. A way considered and utilized to solve such a problem is to start charging the power storage device of the vehicle at charging start time designated by the user.
For example, Japanese Patent Laying-Open No. 7-123599 discloses a charging control device for securely charging a power storage device at charging start time in the way described above. The charging control device checks for problems in the charging system at the moment when the timer is set, and outputs a warning if the charging system has a problem. With this, inexecution of the charging by the problem having existed when the timer was set, can be prevented after the start of charging.
Japanese Patent Laying-Open No. 7-123599 discloses that the charging control device checks for problems at the moment when the timer starts to measure time and at the moment when the timer ends the measurement. However, it never discloses a specific process of the control device when a problem (such as electric power failure) occurs during a period of time from the moment of starting the time measurement to the moment of ending it. In such a case, it is considered that the problem is not detected until the timer ends the time measurement. If the problem in the charging system remains, adverse effects are concerned over not only the charging device but also the vehicle.